I'm not David, but I'll pipe in anyway.

I've got a 351 also. For a while I ran a 14/39 combo. That was essentially the same ratio as 15/42. I used the 39 tooth rear (from the SF) so that I could retain the stock front sprocket. I liked the chain silencer rubber on the sprocket, and it also fits better than a 15. I liked the gearing pretty well for street use. It was also adequate in Moab, although lower gearing would have been a bit better there.

I actually went to a 15/39 when I did a SS1000 and BB1500, but that was a special purpose. After I completed those, I returned to stock (14/42) gearing. Even with the 351, I feel it is the best all-around ratio.

Ron

 

See, that's the problem. You'll feel much more confident with both hands on the bars at speed, rather than nibbling on your fingertips.

 

On the way home from work today I was doing 55mph on the road but riding into a 30mph headwind for for a couple of stretches. Does that qualify as 85mph? I felt just as worked as the 'ol KLX.

Pucker factor was too high to bite my nails, though...